In this project, a system for reversing strial hearing loss by increasing endocochlear potential will be constructed and evaluated in vitro. Strial presbycusis is estimated to affect as many as 7 million people in the US. Recent research has shown that when positive current is injected into the scalae media of quiet-aged gerbils, the endocochlear potential is increased and the hearing thresholds approach normal values of less than 15 dB across all frequencies. The proposed system will increase the endocochlear potential by applying direct current to the scala media, while managing electrode polarization and plating effects. The system will consist of a micro-fluidic electrode, electrode driver, and feedback mechanism to control the endocochlear potential over time. Advanced multi-layer circuit fabrication techniques and UV laser micro-machining will be used to construct various micro-electromechanical (MEM) prototypes. Plating effects will be determined by investigating changes in charge capacity using cyclic voltammetry. Successful completion of the Phase I research will allow in vivo characterization of the electrode system in Phase II. A commercial implant system based on this research could ultimately treat strial-based hearing loss in millions of individuals. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE